Multiple-switch relay



April 12, 1966 1.. B. RONK MULTIPLE-SWITCH RELAY 4 Sheets-Sheet l FiledMarch 26, 1964 FIG. I.

FIGZ.

April 12, 1966 L. B. RONK 3,246,102

MULTIPLE-SWITCH RELAY Filed March 26, 1964 4 Sheets-Sheet 2 UnitedStates Patent 3,246,162 MULTIPLE-SW11 CH RELAY Leroy B. Ronk, Nokomis,Ill., assignor to System Analyzer Corp, Nokcmis, llh, a corporation ofWisconsin Filed Mar. 26, 1264, Ser. No. 355,026 3 Claims. (Cl. 296-484)Among the several objects of the invention may be noted the provision ofimproved motor switching relay apparatus for soft starting ofsingle-phase, capacitor-start, capacitor-run motors and the like; andthe provision of conveniently operable gang-operated transfer switchmeans in apparatus which will handle high inductive reactive current orhighcapacitive reactance current so that comparatively large motors maybe accepted for use on single-phase lines to drive apparatus having lowstarting torque but requiring substantial running torque. Other objectsand features will be in part apparent and in part pointed outhereinafter.

The invention accordingly comprises the mechan cal and electricalelements and combinations of such hiements, features of construction,and arrangements of parts and circuits which will be exemplified in theconstructions hereinafter described, and the scope of which will beindicated in the following claims.

In the accompanying drawings, in which one of various possibleembodiments of the invention is illustrated:

FIG. 1 is a basic wiring diagram illustrating, in a conditionpreliminary to starting, a motor switching circuit employing theinvention;

FIG. 2 is a basic wiring diagram similar to FIG. 1, illustrating arunning condition;

FIG. 3 is a side elevation of a transfer switch assembly shown in aposition for making the FIG. 1 connections;

FIG. 4 is a plan view of FIG. 3;

FIG. 5 is an enlarged end view of a pant of the transfer switchassembly, the view being on line 5-5 of FIG. 3;

FIG. 6 is a rear view of FIG. 3 but showing a position for making thePEG. 2 connections;

FEG. 7 is a schematic layout of the structure shown in F165. 3-6 whereinthe heavy lines indicate current fiow under starting conditions; and

FIG. 8 is a view similar to FIG. 7 wherein the heavy lines indicatecurrent flow under running conditions.

Corresponding reference characters indicate corresponding partsthroughout the several views of the drawings.

At present, utility companies make it a general rule to limit motorsizes acceptable on single-phase lines according to the amount of inrushstarting current. This rule could have exceptions (not now allowed) ifpracticable switch gear were available to start motors driving certainclasses of apparatus which, although having substantial running torque,have low starting torque. Moreover, there are a considerable number ofmotor applications to apparatus as above described having low startingtorque requiring a comparatively small amount of starting current butwhich at running speed have a high running torque requiring highcontinuous running current. An example, but not the only one, is a fandrive which has a low starting torque (small current inrush) and a highrunning torque. The reason for this is that its load increases as thecube of the speed. By means of the present invention, a greater numberof single-phase, ca-

pacitor-start, capacitor-run motors of considerably greater horsepowerare made acceptable on single-phase utility lines for applications suchas above described.

Referring now more particularly to FIG. 1, there is shown at numeral 1the main winding of a single-phase capacitor-start, capacitor-run motorwhich also has a start winding 3. The main winding is connected acrosspower leads L-l and L-2. A conventional starting switch (not shown) isemployed in the leads L1 and L2 and the usual power circuit (also notshown), which for example may apply 220 v. The start winding 3, throughleads 4 and 6 (and a conventional reversing switch, not shown) isadapted to be reversibly connected to the power leads L- i, L-Q.Connected in series with the start winding 3 is a capacitor 8 which isshunted by a second capacitor it series-connected with a conventionalnormally closed centrifugal starting switch 12. The centrifugal switch12 opens when the motor gains a certain speed. Thus, as is conventional,during starting with switch 12 closed there is greater capacitance inseries with coil 3 than under running conditions after the switch 12opens.

The main winding is constructed in two sections 5 and '7, center-tappedas shown at 9. The center tap contains a first transfer switch A Asecond transfer switch A is in shunt connection with switch A andwinding section 5. A third transfer switch A is in shunt connection withswitch A and winding section 7. Shunt connected across theseries-connected section 5 and switch A are a seriesconnected solenoidcoil 23 and fourth transfer switch A It will be understood that thelatter could as well be shunt-connected across the series-connectedsection 7 and switch A without changing the operation, as will appear.Shunt-connected around switch A; is a thermostatic or so-called warpswitch 29 which is in heat-exchange relation with a resistance heater31. The latter is in series connection with a resistance 35 and a fifbhtransfer switch A these series-connected elements being connected acrossthe leads L-d and L-2. Switch 29 closes upon being heated and isself-opening upon cooling. Switch 29 and the heater 31 constitute atime-delay device indicated by dotted lines and numbered -39. This timedelay may be achieved by other than thermostatic means. As will be shownbelow, switches A A A A and A are gang-operated by a switching assemblysuch as shown in FIGS. 3-7.

Switches A A and A are of the heavy-duty type. Switches A A and 29 arein series with substantial resistances and are designed for lighterduty. Switches A and A are, in the present example, so-called microswitches. All of switches A A A A and A form parts of a switchingassembly shown in FIGS. 3-7.

As shown in FIG. 1, switches A A and 12 are normally closed, andswitches A A A and 29 are normally open when the motor is at rest. InFIG. 2, switches A 12 and A are open and switches A A and A are closed.This is the condition when the motor is running at full speed. Switch 29is open, after having temporarily been closed when cold during motoracceleration (see the dotted-line position of switch 29 in FIG. 2 forthe temporary closure).

Referring to FIG. 1, when the leads L-1, L-2 are excited, for example at220 v. (motor shut down), this voltage is applied across the startwinding 3 and the capacitors 8 and 10, the then cold centrifugal switch12 being closed. This also applies 220 v. to the main winding 1. Thisvoltage is divided between the two sections and 7, so that each operatesat 110 v. This results in a so called soft start, meaning that theinrush of current through the series-connected sections 5 and 7 of runwinding 1 is held at a low value during starting acceleration.

The 220 volts are also applied across the heater element 31, theseries-connected resistance and the closed switch A The motor thenaccelerates in a direction depending upon how connections 4 and 6 aremade across the leads L1, L-2 through the said conventional reversingswitch. After a time the heater 31 causes switch 29 to close (see thedotted lines in FIG. 2). This excites solenoid coil 23 which, as will beshown below, by gang operation opens switches A and A and closesswitches A A and A This is illustrated in FIG. 2, which shows that noweach section 5 and 7 of the running winding 1 is individually connecteddirectly across the leads L-1, L-2 and is subject to 220 v. This mayoccur before the motor has fully accelerated. This is the runningcondition wherein heavier current is drawn. At some time duringacceleration, before or after switch 29 has functioned, the centrifugalswitch 12 opens, so that the start winding 3 continues operationconventionally in series only with capacitor 8. When switch A is open asin FIG. 2, it cuts off current from the heater 31, which graduallycools, thus allowing the thermostatic switch 29 when cool to assume itsnormally open position (see the solid lines for switch 29 in both FIGS.1 and 2). Switch 29 is then ready for a subsequent start after motorshut-down. Since the closing of switch A; maintains excitation of thesolenoid coil 23, all of the gang-operated switches A A A A and A duringrunning are held in the position shown in FIG. 2. Normally closed switch12 is held in its open position during running by reason of thecentrifugal action thereon at motor speed. When the line switchsupplying leads L1, L-2 is opened, depriving leads L1, L-2 of voltage,all of the switches return to their normal positions shown in FIG. 1.

In view of the above, it will be seen that under the FIG. 1 startingconditions each section 5 and 7 of the run winding '1 has only 110 v.applied to it, meaning that a comparatively small amount of current isdrawn. This is responsible for the so-called soft start. In the runningcondition of FIG. 2, each section 5 and 7 is impressed with 220 v.,whereupon the required larger continuous load current is drawn.

In FIGS. 3-6, an advantageous transfer assembly is shown, this being animprovement upon the construction shown in my United States Patent3,032,627. The transfer assembly comprises an insulating base 43 onwhich is mounted a laminated core piece 45 which has upstandingprojections 47 and 49 outside of the coil 23. Coil 23 is hollow. Pivotedat 53 on the projection 49 is a rotatable laminated armature 55. Thishas an extending part 57 adapted when the coil 23 is excited to be drawninto the hollow interior portion 51 of the coil 23. The armature alsohas a forwardly projecting portion 59 for engagement with the projection47 when the armature is drawn down (FIG. 6).

Affixed to the armature 55 is a heavy conductive (copper) contact bar 61which moves as the armature moves and is thereby engageable anddisengageable with a fixed contact 63. Return springs 65 bias thearmature in a clockwise direction (FIG. 3). The biases together orcloses contacts 61 and 63, which form switch A Spring 65 are anchored tothe insulating base 43 at 71 and to the armature at 73. Upon excitationof the coil 23, the armature 55 is drawn down against the return actionof springs 65, thus separating the contact 61 from 63, thereby openingswitch A Contact 61 is in the form of a tailpiece extending from thearmature. Contact 63 is bolted to and supported by an angle-shapedstationary conductor 67, supported on the insulating base 43. Conductor67 carries a terminal 69.

On the top of the armature 55 is fastened an insulating crossbar 75 (seeconnecting bolts 77). At the op posite ends of the bar 75 are carriedheavy-duty movable resiliently mounted or floating contacts 79 and 31,respectively. Since these are substantially of the same construction,description of one, i.e., '79, will suffice for both, numbering ofsubsidiary parts of each being the same. Each is L-shaped, having ashort leg part 83 located on the front side of the insulating bar 75,and a long leg 85 located under the bar. A bolt 87, threaded through theshort leg 83, serves to form a rocking support 89 extending loosely intoa recess 91 in the bar 75. In the case of the contact 79, bolt 87 alsoserves as a fastener for a flexible conductor 95. The latter extends andis attached to the central movable contact 61 of switch A Passingloosely through a stepped opening 97 in the long leg 85 is a headed post99. The post 99 extends through an opening in the bar 75 and is heldagainst escape by a cotter key .101 which seats on a washer 103. Aspring 105, which is seated in a socket 102 on the underside of the bar75, presses against the long leg 85 of the contact to rock it in aclockwise direction. The headed post 99 prevents the contact 79 fromdownward escape and from being biased so far forward that the finger 89could escape from pocket 91. In view of the above, it will be seen thatthe movable contacts 79 and 31 are held captive and are resilientlymounted on opposite ends of the bar 75.

Contact 79 is connected with terminal 76 by means of a flexible wire107. Contact 81 is connected with terminal '78 by means of flexible wire109. Each movable contact 79 is crimped as shown at 111 for rocking andwiping engagement with the sloping portion of a fixed contact. The fixedcontacts are identical but the one eugageable by movable contact 79 isnumbered 113, and the one engageable by movable contact 81 is numbered115. Fixed contact 113 and movable contact 79 form switch A Fixedcontact 115 and movable contact 81 form switch A The fixed contact 113of switch A is carried on an L-shaped conductive bracket 1-17 attachedto the base 43 and carrying a terminal 119. The fixed contact 115 ofswitch A is carried on an L-shaped conductive bracket 121 attached tothe base 43 and carrying a terminal 123. Terminal 123 is connected by awire 125 to terminal 69.

It will be understood that the L-shaped brackets 117 and 121 areidentical, and that the fixed contacts 113 and 115 are also identical.As stated above, switches A A and A are of the heavy-duty variety, allof their contacts being composed of heavy copper bar stock. The movablecontacts of switches A and A are carried on the insulating crossbar 75.Riveted to the top of the solenoid core 55 is an inverted channel piece93 between which and the core is telescoped one end of the movablecontact 61 of switch A Two screws 77, passing through the bar 75 andchannel piece 93, are tapped into the telescoped part of contact 61 tohold it in place in connection with the solenoid core 55. This leavesthe other end of the contact 61 as a movable tailpiece.

The mass of armature 55 and insulating cross-bar 75 imparts to itconsiderable inertia, which somewhat delays its starting motion from theFIG. 3 to the FIG. 6 position and also somewhat delays its reversemotion from the FIG. 6 to the FIG. 3 position. Thus in the first casethe switch A will somewhat delay opening due to this inertial mass andthe tension of the springs 105. Moreover, switches A and A will somewhatdelay opening when the solenoid is deenergized, due to the inertialmass. This minimizes the usual noisy report such as would otherwiseoccur when interrupting reactive current. It will also be understoodthat switch A opens before switches A and A close, and that switches Aand A ultimately reopen before switch A recloses.

Attached to the base 43 by means of a bracket 127 is a switch box 129containing two snap switches. These consitiute the switches A and ATheir terminals are numbered 141, 143 and 145. These are of theso-called micro variety and carry comparatively small currents becauseof the comparatively high resistance formed by the coil 23 (in the caseof switch A and the resistances 31 and (in the case of switch A Furtherdetails in regard to these switches are unnecessary, since they are of atype known in the art. In the present case both switches A and A areoperated from a single button 132 by a single lever 131, pivoted at 133to the case 129. This single lever operates both switchessimultaneously. In the position of the lever 131 shown in FIGS. 3 and 4(biased by spring 135), switch A is in its normally open position andswitch A is in its normally closed position, as indicated in FIGS. 1 and5. When the armature is drawn down, as shown by FIG. 6, extension 57strikes lever 13-1 to move it against bias of the spring 135, so as toclose switch A; and open switch A as indicated in FIG. 2.

An advantage of the rotary armature 55 and of carrying the movablecontacts of the switches A A and A on the armature, while supportingtheir contacts 63, 115 and 113 fixedly on the base 43, is that in onemovement switch A, may conveniently be caused to open, and then switchesA and A caused to close. This is accomplished by having the pivot point53 of the armature so positioned (see FIG. 3) that, as the armature 55moves counterclockwise, the movable contacts 79 and 81 descend and themovable contact 61 ascends. Moreover, the descent of the outer portionof the armature finally operates switches A and A Another advantageousfeature is the symmetrical arrangement of the switches A A A A and Arelative to the plane of movement of the armature (FIG. 6). Thus, byhaving switch A; in this plane and swtches A and A symmetricallyflanking the plane in their positions on crossbar 75, together with theswitches being symmetrically disposed relative to this plane andoperated by the lever 131 in the plane, a balanced action is obtained.'It should be noted that the positions of switches A A and A are in asymmetrical triangular relationship (FIG. 4).

FIGS. 7 and 8 are schematic views showing how the switch assembly ofFIGS. 3-6 is interconnected with sections 5 and 7 of the motorwinding 1. These views omit the start Winding 3 and its connections 8,10 and 12. They include the time-delay device 39, which is constitutedby a separately connecti-ble assembly. In these figures, flow of currentthrough the switch assembly is indicated by the use of heavy lines underthe start conditions in FIG. 7, and under the running conditions in FIG.8.

As seen in FIGS. 7 and 8, motor winding section 5 is connected acrossterminals 76 and 78. Motor winding section 7 is connected acrossterminals 69 and 119. Lead L1 is connected to terminal 79. It is alsoconnected to the solenoid coil 23 through terminals 137 and 138, towhich are connected the coil lead wires 139. The other end of the coilis connected through its other terminal 137 to terminal 143 of switch AThe other side of switch A, is connected to terminal 141. Terminal 119is also wired to terminal 141. Terminal 141 also feeds one side ofswitch A The other side of switch A through terminal 145 is connectedthrough heater 31 and resistance 35 with lead L-l. The thermostaticswitch 29 is connected across terminals 141 and 143. As stated, thethermostatic switch 29 and its heater 31 and resistance 35 are notcarried on the assembly shown in FIGS. 3-6.

In view of the above and as shown in FIGS. 7 and 8, it is apparent thatthe external connections for the switch assembly shown in FIGS. 3-6 canbe conveniently made from the motor winding taps and the leads L-1 andL2. In addition, the thermostatic switch 29, heater 31 and resistance 35may conveniently be connected, changed or replaced to suit conditionsunder which it is desired to switch over from the connections shown inFIG. 7 to those shown in FIG. 8. Thus FIG. 7 shows the switcharrangement under starting conditions in which the sections 5 and 7operate in series at v. each. FIG. 8 shows the switch arrangement underrunning conditions, wherein the sections 5 and 7 operate in parallel at220 v. Although a 220 v.-110 v. system has been described, it will beunderstood that the invention is equally useful on analogous system suchas 440 v.-220 v.

In view of the above, it will be seen that the several objects of theinvention are achieved and other advantageous results attained.

As various changes could be made in the above constructions and circuitswithout departing from the scope of the invention, it is intended thatall matter contained in the above description or shown in theaccompanying drawings shall be interpreted as illustrative and not in alimiting sense.

What is claimed is:

1. A multiple-switch relay comprising a base, an electromagnetic coiland pivot means on the base, an armature rotatable with respect to thebase on said pivot means and cooperating with the coil with rockingmovement in a plane passing through the coil, an insulating crossbarcarried on the armature above the coil and extending transversely withits ends on two opposite sides of said plane, a first switch having afixed contact located on the base on a third side of the coil and havinga movable contact carried by the armature and extending in said planetoward said fixed contact, second and third switches having fixedcontacts located on opposite sides of the coil respectively andtransversely of said plane, said second and third switches havingresiliently mounted movable contacts carried adjacent the ends of saidcrossbar for cooperation with their fixed contacts respectively, dualswitch means on the fourth side of the coil opposite the location ofsaid fixed contact of the first switch, means on the armature foroperating said dual switch means, said pivot means being located toprovide a rotary movement of the armature and said insulating barcarried thereby such that upon excitation of the coil the movablecontact of the first switch rises from its fixed contact and thereafterthe resiliently mounted movable contacts of the second and thirdswitches descend resiliently on their fixed contacts, and said dualswitch means is operated by descent of the armature.

2. A multiple-switch relay comprising a base, an upright electromagneticcoil and transverse pivot means on the base, an armature rotatable withrespect to the base on said transverse pivot means and movable into andout of the coil with rocking movement in a plane passing lengthwisethrough the coil, an insulating crossbar carried on the armature andextending transversely with its ends on two opposite sides of saidplane, a first switch having a fixed contact located on the base on athird side of the coil in said plane and having a movable contactcarried by the armature and movable in said plane to and from said fixedcontact, second and third switches having fixed contacts located on saidtwo opposite sides of the coil, said second and third switches havingresiliently movable contacts hinged adjacent the ends of said crossbar,the movable contacts of the second and third switches beingsymmetrically disposed in a triangular relationship to the movablecontact of the first switch, the fixed contacts of the second and thirdswitches being symmetrically disposed in a triangular relationship tothe fixed contact of the first switch, normally open and normally closeddual switch means on the fourth of the coil opposite the location ofsaid fixed contact of the first switch, common control means forsimultaneously operating the dual switches, drive means on the armatureopposite the fixed contact of said first switch for operating said dualswitch control means, said pivot means being located to provide a rotarymovement of the armature and said insulating bar carried thereby suchthat upon excitation of the coil the arma- I s 8 ture is pulled downinto it and the movable contact of the Refezences Cited by the Examinerfirst switch rises from its fixed contact and thereafter UNITED STATESPATENTS the movable contacts of the second and third switches A descendresiliently upon their fixed contacts, and said 1,736,391 8/1929 Goff200107 dual switch means is operated by descend of said drive 52,735,968 2/1956 Boghle et a1 200 87 X means located on the armature3,115,561 12/1963 Lewis et al 20()87 3. A relay made according to claim2, wherein the movable contacts of the second and third switches areresil- BERNARD GILHEANY Examiner iently mounted on said insulatedcrossbar. R. N. ENVALL, JR., Assistant Examiner.

1. A MULTIPLE-SWITCH RELAY COMPRISING A BASE, AN ELECTROMAGNETIC COILAND PIVOT MEANS ON THE BASE, AN ARMATURE ROTATABLE WITH RESPECT TO THEBASE ON SAID PIVOT MEANS AND COOPERATING WITH THE COIL WITH ROCKINGMOVEMENT IN A PLANE PASSING THROUGH THE COIL, AN INSULATING CROSSBARCARRIED ON THE ARMATURE ABOVE THE COIL AND EXTENDING TRANSVERSELY WITHITS ENDS ON TWO OPPOSITE SIDES OF SAID PLANE, A FIRST SWITCH HAVING AFIXED CONTACT LOCATED ON THE BASE ON A THIRD SIDE OF THE COIL AND HAVINGA MOVABLE CONTACT CARRIED BY THE ARMATURE AND EXTENDING IN SAID PLANETOWARD SAID FIXED CONTACT, SECOND AND THIRD SWITCHES HAVING FIXEDCONTACTS LOCATED ON OPPOSITE SIDES OF THE COIL RESPECTIVELY ANDTRANSVERSELY OF SAID PLANE, SAID SECOND AND THIRD SWITCHES HAVINGRESILIENTLY MOUNTED MOVABLE CONTACTS CARRIED ADJACENT THE ENDS OF SAIDCROSSBAR FOR COOPERATION WITH THEIR FIXED CONTACTS RESPECTIVELY, DUAL